html,body {
    width: 100%;
    height: 100%;
    background-color: grey;
    div {
        width: 200px;
        height: 200px;
        background-color: green;
        position: absolute;
        z-index: 100;
        border: 1px solid black;
    }
    .abc {
        width: 100px;
        height: 100px;
        border: 2px solid black;
    }
}


